DataAsyncCommand.AsyncDeriveSchema Method

Derives, in an asynchronous manner, the schema of the specified command.

Namespace: Microsoft.VisualStudio.Data
Assembly: Microsoft.VisualStudio.Data (in Microsoft.VisualStudio.Data.dll)

Syntax

'宣言
Public Overridable Sub AsyncDeriveSchema ( _
    command As String, _
    commandType As Integer, _
    parameters As DataParameter(), _
    commandTimeout As Integer, _
    asyncCommandEvents As DataAsyncCommandEvents _
)
'使用
Dim instance As DataAsyncCommand
Dim command As String
Dim commandType As Integer
Dim parameters As DataParameter()
Dim commandTimeout As Integer
Dim asyncCommandEvents As DataAsyncCommandEvents

instance.AsyncDeriveSchema(command, commandType, _
    parameters, commandTimeout, asyncCommandEvents)

public virtual void AsyncDeriveSchema(
    string command,
    int commandType,
    DataParameter[] parameters,
    int commandTimeout,
    DataAsyncCommandEvents asyncCommandEvents
)

public:
virtual void AsyncDeriveSchema(
    String^ command, 
    int commandType, 
    array<DataParameter^>^ parameters, 
    int commandTimeout, 
    DataAsyncCommandEvents^ asyncCommandEvents
)

public function AsyncDeriveSchema(
    command : String, 
    commandType : int, 
    parameters : DataParameter[], 
    commandTimeout : int, 
    asyncCommandEvents : DataAsyncCommandEvents
)

Parameters

command
Type: System.String

The command for which the schema is derived.

commandType
Type: System.Int32

Format of the command string.

parameters
Type: []

A list of parameters to pass with the command.

commandTimeout
Type: System.Int32

Amount of time, in seconds, before which the command times out.

asyncCommandEvents
Type: Microsoft.VisualStudio.Data.DataAsyncCommandEvents

The object on which this method calls back as the command progresses.

Exceptions

Exception	Condition
ArgumentNullException	The command or asyncCommandEvents are null.
ArgumentException	The commandType specifies an invalid type.
ArgumentOutOfRangeException	The commandTimeout is less than -1.
NotSupportedException	The provider does not support this method.

Remarks

This method performs the same operation as the DeriveSchema method, but in an asynchronous manner.

If the value of the commandTimeout parameter is 0, there is no timeout (or, timeout is infinite); if the value is -1, the timeout period is that set by the data provider.

注意

Other exceptions that occur indicate that the parameter derivation failed for a provider-specified reason.

Permissions

Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.